2-methoxy-4-methylphenyl-n-methylcarbamate and insecticidal compositions containing the same

ABSTRACT

Novel 2-methoxy-4-methylphenyl-N-methyl-carbamate and insecticidal compositions comprising the same as an active ingredient.

United States Patent Nishimura et al.

[ June 20, 1972 [72] Inventors: Tatsumi Nishimura, Shimizu; Tadahiko lnoue, Ogasa-gun; Talteo Tsuboi, lkedaz- Masaru Kado, Yokohama, all of .I apan [73] Assignce: Kumill Chemical Industry Co., Ltd.,

Tokyo, Japan [22] Filed: July 2, 1969 [21] Appl. No.: 838,700

[52] U.S. Cl. ..424/300, 260/479 C [51 Int. Cl. ..C07c 125/06, AOln 9/24 [58] Field of Search ..260/479 C; 424/300 [56] ReferencesClted OTHER PUBLICATIONS Metcalf et al., Agricultural and Food Chem., (May/June, 1965 pages 224 and 226.

Primary Examiner-James A. Patten AnomeyStevens, Davis, Miller 84 Mosher ABSTRACT 2 Claims, No Drawings 2-METHOXY-4-METHYLPllENYL-N- METHYLCARBAMATE AND INSECTICIDAL. COMPOSlTlONS CONTAINING THE SAME The present invention relates to a novel N-methylcarbamate and an insecticidalcomposition containingthe N-methylcar- 5 bamate as an active ingredient,-and more particularly to 2- methoxy-4-methylphenyl-N-methylcarbamate.

An object of the present invention is to provide 2-methoxy- 4-methylphenyl-N-methylcarbamate having an excellent insecticidal activity and an insecticidal composition containing the'same as an active ingredient.

Another object of the invention is to provide an insecticidal composition, which can develop an excellent insecticidal activity when spread on a rice field and is low in'toxicity'against war'mblooded animals.

However, in control of green rice leafhopper, it is-considerably desirable to control of small brownplant= hopper simultaneously, in order to prevent rice stripe virus which is transmitted by smaller brown plant hopper and is now widely increased so becomes an important problem in rice production.

Since many conventional carbamate series insecticides have not been freely satisfactory, it has been usual thatPl-lC (2- isopropoxyphenyl N-methyl-carbamate), which'has an activity againstthe smaller brown plant hopper but has a short residual effectiveness, is used together with some organic phosphate series insecticide or Bl-lC which are effective to the smaller brown plant hopper.

The inventors have found from the result of various investigations that the compound used as an active ingredient Calculated value 61.52 6.712 7.175

Found value 61.31.15 6.85 7.20

IR spectrum (KBr method): 3,330 cm"; 2,960 cm", l,7l 8 cm", 1,610.cm 1,- 1,5l0 cm", 1,288 cm, 1,264cm '1, 1,210 cm", 1,154 CUP, 1,130 cm "1, 1,040 cm", 950 cm, 860 cm", 830cm", 770 emf, 720 cm",

'Thissubstance is identified withtheobject compound from the above analytical data.

Thecompound accordingto the, present invention'is a white prism; crystal andiseasily solublein anorganic'solvent but poorly water-soluble.

In an application foragriculturaland horticultural insecticide, the compound of the inventionis mixed with a carrier (diluent) and, if necessary, a surfactant to, formulate dust, wettable; powder,.emulsifiable concentrateor granule, which is directly spread or used after diluted to a suitable concentration.

The invention will: be explained with respect to some preparation examples, but the additives and the mixture ratio can be varied in a widerange. The percent means by weight.

' EXAMPLE 1 ousr Two percent of the. compound according to the invention, 5 percent of diatomaceousearth, 50 percent of kaolin and 43 percent of talcweremixed and pulverized, and the resulting powder is-dusted. I

EXAMPLE Z'WE'I'TABLE POWDER Twenty percent of the compound oftheinvention, 20 percent of diatomaceous earth, 55 percentof kaolin and 5 percent of'a mixture of polyoxyethylene alkylaryl ether, an'dorganic sulfonate, which is a spreading-agent, were mixediand pulverized to form a wettable, powder, which is used as a suspension in water.

'EXAMRLE 3 EMULSIFIABLECONCENTRATE according to the invention, shows an excellent insecticidal ac- Twenty percenL-of the compound of the invention, 60 per tivity againstboth the green rice leathopper and the smaller brown plant hopper.

Furthermore, the compound according-to the invention has a higher durability, so-called residual activity as compared with conventional many carbamate series compounds. 45

ty against warm blooded animals. Namely, an oral acute toxicity for mouse (LD-SO) is more than 300 mg/kg, and the compound of the present invention is extremely low in toxicity.

2-methoxy-4-methylphenyl-N-methylcarbamate of the active ingredient according to thepresent'invention is synthes- 5 ized by the following method.

Twenty-five g (0.18 mole) of 2-methoxy-4-methylphenol is dissolved in 100cc of acetone and theretoisadded 10.3 g

(0.18 mole) of methyl isocyanate and further 0.5 of

cent of xylene and 20 percentof amixture of polyoxyethylene alkylaryletherand organicsulfonate, which is an emulsifier, were mixedand-dissolved to form anemulsifiableconcentrate, which is usedafter'dilutedwith water.

" EXAMPLE 4 GRANULE' i In arotary-drum mixer was charged 92' percent of lime stonepowder of 10 to20 meshesand thereon wassprayed a solution dissolving 4 percent of polyoxyethylene alkylaryl ether of 4 .percentof methanol. The mixer was rotated until the surface of the powder'wasuniformly coated withthe solution. Then 4 percent of the compound of the inventionpulverized'less than'300'meshes was added into the mixer and the mixer-wasrotateduntilthecompoundadhered onthe surface of the coated powder uniformly. and then the coated powder- I was passed through ascreen und'eran. air flow and dried to form granules. r

As described above, thecompound according to the present triethylamine is added as a catalyst. The reaction vessel is f is used in form of dust wgnalf'lc P l' 'l emulsifiableconcentrateand granule. As. the solid carrier used'for When the reaction vessel is opened after the night, an irritative oder of methyl isocyanate is lost no'longer and the reaction is completed.

After the completion of the reaction, the solvent of acetone is distilled off under a reduced pressure, and to, the residue is added ligroin to precipitate crystals, which are filtered off and recrystallized by adding ligroin to obtain 34 g of pure and white prism crystal having a melting point of 100' to 101 C (Yield 97 percent).

Elemental analysis as C .H,,N0, v

may be-madeof water and organic solvents such as alcohol,

dust,:wettab1e powder and granule, mention may be made of clay,*feldspar, mica,'mutshell, cellulose powder, residue of 7 plant extract, .activecarbon and the like in additionto the above described diatomaceous earth,.kaolin and limestone. As theiliquid carrierused for emulsifiable concentrate, use

benzene, xylene, toluene, dimethyl-sulfoxide and mineral oil fraction. As the surfactant, mention may be made of polyoxyethylene alkylaryl ether, organic sulfonate, fatty acid, a condensate of fatty alcohol or fatty-substituted phenol and ethylene. oxide, fatty esters or ethers of polyhydric alcohol and a bloclccopolymer of ethylene oxide and propylene oxide. Further, other anionic or non-ionic surfactants can also be used. 7

Then experimental examples for preventing harmful insects by means of the active compound according to the present invention will be explained.

EXPERIMENTAL EXAMPLE 1 Test for controlling the housefly The houseflies (Takatsuki strain) were bred on a culture of beam-curds lees and 3 days after fledged female adults were anesthetized with carbon dioxide gas. On the back of the breast of the adult was applied dropwise l p.I of the sample, which had been diluted with acetone to a predetermined concentration, by means of a microsyringe and 24 hours after treated, number of dead insects was recorded.

The breeding and experiment were carried out under the environmental condition of 25 C and 75 percent humidity respectively. When the mortality was more than 90 percent,

the experiment was effected with the sample having a lower.

concentration of the active ingredient and LD per one adult was measured. The experimental results are shown in the following Table l.

TABLE 1 LD50 admin- LD for the istered orally housefly to mouse Active ingredient (7/ Q) (mg./kg.)

(J l h (I. 35 300 1 I I It N u 0 um ll (tll 'v present, compound) (J a 0. 7" 30 0 l l 0 J --O/ -()Clla n C II;

(comparative compound) 0 H3 2. 31 30 C II I; 0 i

NC-O. 0 CH3 II (comparative compound) CH3 0. 56 44 O C H C Ha C I I 0 (Sevin,-" comparative compound) "Z-isopropoxyphenyl-N-mcthylearbamate. *'l-naphthyl-N-methylcarbamate.

EXPERIMENTAL EXAMPLE 2 "Test for preventing the smaller brown plant hopper l. Contact test Emulsiflable concentrate of sample formulated as described in Example 3 was diluted with water at a concentration of 2,

- l0, 50,0r 100 ppm.'Diluted-solution was sprayed on potted rice plants by means of a spray nozzle. at a rate of 100 l/l0 ares. After drying in air, the rice plants were cut at the root side, and then the cut rice plants were put into a glass bottle containing water and covered with a cage. Twenty female adults of the smaller brown plant hopper were freed in the cage and after 24 hours, the median lethal concentration (LC was measured.

2. Systemic activity test The diluted solution used in the above contact test was charged into a glass tubular bottle and the cut rice stem was put thereinto. The stem was coated with veseline at a distance of 1 cm above the liquid level so as to prevent the rising of the solution by capillary effect. Then the stem was fixed with a wire and covered with a cage, and thereafter the insects to be tested were freed therein. The median lethal concentration (LC,,,) was determined from the mortality after 24 hours.

The results are shown in the following Table 2.

Test for preventing the green rice leafhopper l. Contact test Emulsifiable concentrate of sample formulated as described in Example 3 was diluted with water at a concentration of 2, 10, 50, or ppm. Diluted solution was sprayed on potted rice plants by means of a spray nozzle at a rate of 100 l/lO ares. After drying in air, the rice plants were cut at the root side, and then the cut rice plants were put into a glass bottle containing water and covered with a cage. Twenty female adults of the green rice leafhopper were freed in the cage and after 24 hours, the median lethal concentration (LCM)v was measured.

2. Systemic activity test The diluted solution used in the above contact test was charged in a glass tubular bottle and the cut rice stem was put thereinto. The stem was coated with vaseline at a distance of 1 cm above the liquid level so as to prevent the rising of the solution by capillary movement. Then the stem was fixed with a wire and covered with a cage, and thereafter the insects to be tested were freed therein. The median lethal concentration (LC was determined from the mortality after 24 hours.

The result is shown in the following Table 3.

(Sevin, comparative compound) Residual effectiveness against the smaller brown plant hopper limulsifiahle concentrate of the compound as shown in Example 3 was diluted with water to a concentration of 500 ppm. The diluted solution was sprayed on potted rice plants by means of a spray nozzle at a rate of 100 l/l ares. Three, 5, 7, l0, l4, and 20 days after sprayed, the rice plants were cut at the root sides and the cut rice plants were put into a glass tubular bottle containing water, respectively. The rice plant was covered with a cage and twenty female adults of the smaller brown plant hopper were freed therein, whereby the mortality after 24 hours was measured. Each experiment was repeated three times.

tested having a predetermined concentration was sprayed on the rice stem in a rate of l00cc/3 pots by means of a spray gun.

Three days after sprayed, the rice stem was cut and opened and the number of died or living insects was calculated. The experiment (three pots) was repeated three times.

EXPERIMENTAL EXAMPLE 6 l0 Effectiveness on the leafhoppers when various granules are sprayed on the water surface of paddy field. Insects to be tested:

female adults of green rice leafhopper (Kikukawa Strain), female adults of smaller brown plant hopper (Kikukawa The results are shown in the following Table 4. 15 ain) TABLE 4 Mortality (percent) 7 2 1 14 Active ingredient days days days days days day OCH; 100 100 100 100 0s 03 HCa\ E J (the present compound) CH3 100 100 73 32 0 0 OCH CH: OH: N NC-O (PHC, comparative compound) g 74 10 0 i 0CN (Sevin, comparative compound) EXPERIMENTAL EXAMPLE 5 Test method:

45 The paddy field rice plants were transplanted in a Insecticidal activity against the first generation of rice stem borer The rice plants were cultivated to'a length of about cm in a pot having a diameter of l5 cm and about 50 ova per pot of the rice stem borer just before hatching were inoculated on the stem of'the rice plant. After 7 days, the solution to be polybucket of 25X32X10cm and 10 days after transplanted, the polybucket was filled with water to a depth of 3 to 4 cm and a predetermined amount of each active ingredient as shown in the following Table 6 was spread by hand. The rice 50 plant in the polybucket was covered with a cage and at 3 and 7 TABLE 6 7 Green rice leafhopper Smaller brown plant hopper Content 3 days 7 days 3 days 7 days of active ingre- Number M or- Number .\Ior Number .\for- Number Mordient of inmm intality of intality of in- 'tallty Active ingredient percent sects percent sects percent sects percent sects percent Present compound... 4 19 100 39 82.0 37. 100 100 Comparative compoun Bassa 1 4 16 94. 0 24 70. 8 56 37. 6 36 50. 0 Tsurnaclde 4 20 100 31 35. 5 33 45. 5 -11 34. 2 Mlpcln 5 12 91. 6 27 70.4 42 31.0 49 5982 Sevm 8 20 100 3'2 78.2 39 97.5 44.5 I Qsec-butylphenyl-N-methylcarbamate; 2 3-methylphenyl-N-methylcarbamate; 3 2-lsopropylphem'l -N-mctl1y1carbar nate. p TABLE 5 days after spread, insects to be tested were freed in the cage and the number of living or died insects after 24 was meay sured.

p Active ingredient cent) Amount of granule used. 8 kg/lO ares Present compound 87. 5 7'0 On-C4He s. 5 What is claimed is:

u-omparntivo L'Ollllltllllltl) l. 2-methoxy-4-methylphenyl-N-methylcarbamate.

2. An insecticidal composition comprising as an active ingredient an insecticidally effective amount of 2-methoxy-4- methylphenyl-N-methylcarbamate and an inert carrier.

t a a a e 

2. An insecticidal composition comprising as an active ingredient an insecticidally effective amount of 2-methoxy-4-methylphenyl-N-methylcarbamate and an inert carrier. 